Detent.



W. FERRIS.

DETENT- APPLICATION FILED FEB. 23,1918- Patented Mar. 11,1919.

fmvenzar 77a} Z567 2577 33 UNTTED STATES PATENT QFFICE.

WALTER FERBIS, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO BUCYRUS COMPANY, OFSOUTH MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN. I

DETENT.

Specification of Letters Patent.

Original application filed March 1, 1917, Serial No. 151,859. Dividedand this application filed February 23, 1918. Serial No. 218,743.

To all whom it may concern:

Be it known that I, WALTER FERRIS, a citizen of the United States,residing at 'Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented a certain new and useful Improvement inDetents, of which the following is a specification, the same being adivisional application of Serial No. 151,859, filedMarch 1, 1917.

My invention relates to improvements in detents such as may be used inconnection with jib hoistsand automatic interlocking devices forlocomotive cranes but is equally well adapted for use under many othercircumstances.

My invention, therefore,"has for one object to'provide a detent orautomatic stop which will be normally always in working relation withthe ratchet wheel. Another object is to provide a detent which cannot bethrown off by sudden pressure or spinning of the ratchet wheel, a detentwhich will be yieldingly moved toward and from the ratchet wheel and apart of which will always be in operative relation except whenpositively withdrawn by the operator.

Figure 1 is a side elevation of a part of a crane featured in my device;

Fig. 2 is a side elevation onan enlarged scale showing a detail of thedetent;

, Like parts are indicated by like letters in allthefigures.

.A is a supporting frame. Rotatably mounted in it is a shaft A Rotatablymounted on the shaft is a drum A Keyed to this drum is a ratchet wheel AA is a clutch housing containing a clutch not shown whereby the shaftwhich is rotated by any suitable source of powernot here shown may beconnected or disconnected to the drumand'ratchet wheel. A is a leverwhereby the clutch may be controlled by the ,perator. V

The ratchet. wheelis provided with a plurality of teeth B having curvedforward detent engaging surfaces B and curved rear wardly extendingsurfaces l3 each surface terminatedat and-merged in a'cylindricalbearing surface'B l3 is an eccentric bear ing disk mounted forrotationeccentrically on the pin 13 and yieldingly thrust forward andheld against rotation by the plunger'B slidablein a lug B and held inthe outer or forward positionby a "compression spring teeth then theother will rest upon the cylindrical' surface B and their relativedistance apart is such that when one of them is caught on the point ofone of the teeth as shown in Fig. 2 the other will just rest on thecylindrical surface so that if for instance B slips off 13 will not beflung out or not be caught in the air but will be right against thecylindrical surface and as the ratchet wheel turns the tooth B willengage the dog B and since that tooth has a curved surface it will holdthe dog down and there will be no possibility of its jumping out andpermitting the load to escape.

C is a hand link slidable in the guide 0 and notched to engage the guidefor engagement and control of the ratchet by the operator. This link ispivoted on one end of the bell crank lever C The other end of the bellcrank lever has pivoted to it the two thrust bars C C slidable each in asocket C C pivoted on the lugs C C on the dogs B B. C C are springsinterposed between the bars C C and the blocks C C whereby there is ayielding operating connection between each of the dogs and the handcontrol and when in the position shown in Fig. 1 these two springs arecompressed and tend to hold the dogs down 'With the hand control in theposition 1 where there is no reaction or no unusual load 7 over theinclined'back side of the tooth and dropping down against thecylindrical surface. The fact that the dogs are so spaced that therenever is a time when one of them is not against the inner cylindricalsurface and therefore in line with a tooth makes it perfectly surethatno matter when the clutch be disengaged orv no matter what happens oneof these'dogs will stop rotation of the ratchet wheel and the partsassociated with it.

The holding dogsare mounted on a large on the eccentric reacting againstthe buffer spring is to form a yielding abutment to absorb shocksreceived through the ratchet wheel. 7 r

In applying the interlocking device to this part of the mechanism thecam shaped fprojectinglug upon the eccentric, it will be noted, islocatedin such a position that carried by either pawl, the buffer springwill push the eccentric around to this no load position so that the camshaped locking lug crosses the path of the lower shoulder on the slidingbar and this prevents any outer movement ofthe'bar, and thereforeprevents disengagement of the clutch. The purpose of-the light springwith the long travel is to get such positive and ample movement of theinterlocking lug when, the load carried. by the pawls is at a minimum ormerely due to the weight of the jib sufiicient to insure a properinterlocking because the heavier stiffer spring might very easily nottravel a sufficient distance to provide a positive and definiteinterlock.

The dogs may be withdrawn from engagement with the ratchet by the reachrods and 7 these dogs being that the reach rodswhile pivoted to thelever are slid able in the pivotalheadsso that they may thrust the dogsinwardly by a positive connection but slide outwardly away from the dogswhen moved inthe opposite direction. However, when so moved they causetheexertion of a tension inthe coil springs tending yieldingly to drawthe dogs outwardly. WVhenit is desired to -withdrawthe dogsfroniengagement with V the ratchet the operatinglever or connecting armismoved to the right rotating the short lever, drawing up on the reachrod andexerting-a tension in thesprings. Either pawl will, of course,immediately draw away from the rod, the other one being held by the loadon the rod will not be free t01move,,,but since power is applied and thedrum is rotated in a clockwise direction, the dog will be released andthe spring will instantly draw it away from the ratchet teeth. Apossibility of accident lies in the possible engagement of oneof thedogswith the overhanging end periphery through one half of the are beingcircular, and the remaining half gradually rising to the height of theratchet tooth. This circular periphery is at the minimum radius of therootlof thetooth and it is obvious from inspection that when either oneY of thedogs is either engaged fully or partially with a ratchet tooth,the other is lying against the surface of minimum radius and in positionof engagement, although removed by one half of a tooth pitch from thetooth with which it would next engage. Therefore if one dogshould slipout theother would immediately engage with the same tooth of the ratchetwheel from which the first had slippedas soon as the ratchetwheel hadrevolved through one half of the tooth pitch. This happens no matterwhich dog slips- .7 If it is the upper dog the lower one will catch onthe'same tooth as the ratchet wheel comes around. Ifit is the lowerdogthatfirst engages, the upper will catch on the next tooth as it comesaround so there is no possibility of a slip getting away from both thesedogs under any circumstances. 7 'Iclaiin':. 7 1. In a detent motion,aratchet wheel, a

pawl engagingsaid ratchet wheel, means for V keeping it in suchengagement, and a yielding operating memberwhich maybe set'to causewithdrawal ofthe pawl when load is relieved therefrom. V I p 7 2. In a'detent gear, a ratchet wheel, and two staggered pawls coactingtherewith, the profile. of the ratchet teeth being so formed that thepoints of both pawls can simultanee ously occupy the positionof "minimumradius.

V 3. In a detent gear, ratchet whefel and two pivoted pawls engaging.therewith so as being. so formed that if one should slip put I of.engagementthe. vJarretis. alread in. position for, engagement withoutfurther revolii tion uponitsipivot. I 4.,A' detent comprising ratchetwheel having a plurality. oflteeth projecting outwardly therefromcylindrical surfaces intermediate saidlte'eth nearerithe center ofrotation than the effective dog engaging to dividethe ratchet toothpitch, the awn tooth surface, two tooth engaging dogs arranged adjacentone another and spaced angularly one from another the distance betweenthe dogs being such that one of them can always be in register with oneof the teeth and yielding means for holding said dogs against the wheel.

5. A detent comprising a cylindrical wheel and a plurality of teethprojecting outwardly therefrom holding dogs in opposition thereto andmeans for yieldingly forcing them against the wheel the distance betweenthe dogs being such that one ofthem isalways in line with a tooth, meansfor positivelyv moving said dogs into and out of operative relation saidmeans comprising a controlling rod a lever actuating it; the yieldingmeans being rigidly attached to such rod.

6'. A detent comprising a cylindrically surfaced wheel and a pluralityof teeth pro in opposition thereto and means for yieldingly forcing themagainst the wheel the distance between the dogs being such that one ofthem is always in line with a tooth a yielding abutment upon which suchdogs are mounted said abutment comprising an eccentric disk the dogsbeing rotatable about the center of the disk the disk itself being,

about an eccentric bearing yielding means for resisting the rotation ofsuch disk and holding the dogs against the bodily movement therewith. V

8. A detent comprising a wheel and a plurality of teeth, projectingoutwardly therefrom, holding dogs in opposition thereto, said dogsmounted on an eccentric bearing, yielding means operating against theeccentric bearing, and yielding means operating against the holdingdogs, adapted to force them into engagement with the wheel.

: 9. A detent comprising a cylindrical wheel and a plurality of teethprojecting outwardly therefrom, holding dogs in opposition thereto, saiddogs mounted on an eccentric bearing disk, yielding means operatingagainst the eccentric bearing disk, and yielding means operating againstthe holding dogs, adapted to force them into engagement with the wheel.

10. A detent comprising a cylindrical wheel and a plurality of teethprojecting outwardly therefrom, holding dogs in opposition thereto, saiddogs mounted on an eccentric bearing dlsk, yielding means operadapted toforce them into engagement with V the wheel, and additional means forpositively moving the dogs into and out of en- 7 gagement with thewheel, comprising a controlling rod attached to the yielding means. Intestimony whereof I afiix my signature, in the presence of twowitnesses, this 13th day of February, 1918.

WALTER rnnnrs;

' Witnesses: E. J. WILKIE,

WALTER PLEHN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington; I). G.

